1. Field of the Invention
This invention pertains generally to the field of decrypting and executing code stored as encrypted instructions in a storage device.
2. Description of the Related Art
In a system where operational software is encrypted prior to execution, converting source code or instructions into executable form can be problematic. For example, one method comprises bulk decryption of the entire set of encrypted source code or instructions and storing the decrypted code into one or more memory banks; however, this requires a significant amount of onboard memory plus extended power-up latency.
In another example, a method could comprise the decrypting of blocks or sets of code or instructions as needed; however, this causes power inefficiencies due to unneeded code begin fetched and decrypted. In another example, a method could comprise a decryption “on the fly.” While this method may address the non-usage of excess memory and inefficient power consumption of the two of the previous examples, it comes with an instruction by instruction latency due to the additional decryption processing that is not combinatorial in nature.